The present invention relates, in general, to electronics, and more particularly, to methods of forming packaging structures for semiconductor devices.
In the past, the semiconductor industry utilized various methods and structures to form packages that encapsulated a semiconductor die and provided leads for electrically connecting to the semiconductor die. In one type of semiconductor package, the semiconductor die was mounted flip-chip style between two leadframes. The upper leadframe had a continuous flat surface on which the die was mounted and a foot that was mechanically attached to the lower leadframe. This configuration provided an inaccurate positioning of the semiconductor die to the lower leadframe. In addition, the various parts and assembly steps increased the cost of the encapsulated semiconductor device.
Accordingly, it is desirable to have a semiconductor package that accurately positions the semiconductor die and that provides a lower cost package.
For simplicity and clarity of the illustration, elements in the figures are not necessarily to scale, and the same reference numbers in different figures denote the same elements. Additionally, descriptions and details of well-known steps and elements are omitted for simplicity of the description. As used herein an electrode of a semiconductor die means an element of a device that is formed as a portion of an active element of the semiconductor die that carries current through the device such as a source or a drain or a gate of an MOS transistor or an emitter or a collector or a base of a bipolar transistor or a cathode or anode of a diode. The use of the word approximately or substantially means that a value of an element has a parameter that is expected to be close to a stated value or position. However, as is well known in the art there are always minor variances that prevent the values or positions from being exactly as stated. It is well established in the art that variances of up to at least ten per cent (10%) are reasonable variances from the ideal goal of exactly as described.